This invention relates to chewing gum. More particularly, it relates to a method of improving chewing gum to reduce spots of unincorporated alditol bulking agents, such as sorbitol, in manufactured gum, which can impede processing and may show up as product defects.
Sugar alcohols, also known as alditols, are a common ingredient in so-called "sugarless gums". Sorbitol, a six-carbon sugar alcohol having the empirical formula C.sub.6 H.sub.14 O.sub.6, is the most common ingredient in such chewing gums, although mannitol and xylitol are also commonly used. These sugar alcohols serve as bulking agents, i.e., major ingredients to provide bulk to the chewing gum composition, and to provide sweetness to the chewing gum. Alditols are also occasionally added to sugar gums for various reasons. Sheets or pieces of gum which include bulking agents such as sorbitol or mannitol, however, may contain spots of unincorporated bulking agents. Such spots can impede processing and may show up as product defects.
Normal gum production produces scraps of gum (known as gum scrap, trim, rework or waste material) which must be discarded as waste if not used by being included in subsequently processed gum. For example, Kramer et al. U.S. Pat. No. 4,555,407, issued Nov. 26, 1985, describes as prior art the use of 7 to 15 weight percent of rework as an ingredient in chewing gum compositions, and discloses a continuous process of forming chewing gum slabs which may reduce the proportion of rework to about 5 percent. According to traditional batch processing of chewing gum compositions, trim is added after the addition of bulking agents is started.
Attempts to control bulking agent spotting in the past have been unsuccessful. Early addition of liquids and longer mixing schedules have proven ineffective in controlling spots of bulking agent in the past. Experiments have shown, for example, that early additions of glycerin softener without early trim addition, and early additions of trim without early glycerin softener or lubricant addition, both result in high spot counts. Furthermore, early addition of trim without early addition of softener is undesirable because of the need to avoid excessive mixer loads (too much torque will break the mixer blade or damage the mixer motor).